Feature enhancement request has been registered in our issue tracking system with issue id: SLIDESNET-35757. We will notify you via this forum thread once the feature gets available in the latest version of Aspose.Slides.
I found a method to get the text of the header and footer using Aspose.Slides 14.7.
Dim oPresentation As New Presentation(“my.pptx”)
For Each oSlide As Slide In oPresentation.Slides
For Each oShape As Shape In oSlide.Shapes
If oShape.Placeholder IsNot Nothing AndAlso (oShape.Placeholder.Type = PlaceholderType.Header Or oShape.Placeholder.Type = PlaceholderType.Footer) Then
Dim str As String = CType(oShape, IAutoShape).TextFrame.Text
I am glad to know that you are able to implement the workaround at you end. Please feel free to contact support in case you need any further assistance.